VoIP telephony service providers are entities that provide VoIP telecommunications services to their customers. To achieve this goal the service providers manage large VoIP telephony networks that utilize the Internet as the fundamental infrastructure to exchange voice data between endpoints. While the Internet may be the conduit for carrying voice traffic, a series of routers, switches, telephony servers, databases, communication devices, and other components are needed to actually manage and move the voice traffic, in the form of IP data packets, through the vast network plumbing that is the Internet.
Traditional telephony used to be solely circuit-switched and was managed by a relatively small number of service providers known as incumbent local exchange carriers (ILECs) like AT&T and Verizon. Circuit switched telephony operated (and still operates) over what is commonly known as the public switched telephone network (PSTN). The PSTN is organized as a series of switches and gateways that connect one endpoint to another over a single predetermined dedicated path. That is, there is a dedicated voice path from endpoint to endpoint (e.g., phone to phone) that is not shared by any other communication session (e.g., phone call) for the duration of that call. In practice, a calling phone requests and receives a dedicated circuit connection to the called phone, and if the called phone answers that direct circuit path remains dedicated to those endpoints for the duration of the call.
VoIP telephony systems differ from the legacy circuit-switched telephony systems. VoIP telephony does not rely on a dedicated path or circuit between endpoints. Rather, the end user device digitizes analog audio and forms it into an IP packet stream. The IP packet stream is then addressed to a destination device and routed much the same as other Internet traffic—that is it may share a “connection” and mingle with other IP data as it gets routed to its destination. When it reaches its destination, a device on the other end can re-assemble the original IP packet stream and convert it to analog audio.
Moreover, there are inter-connection points in VoIP telephony networks that allow VoIP calls and circuit-switched calls to connect with one another such that a VoIP end user can make and receive calls with a circuit-switched end user despite the network differences. It should also be noted that traditional cellular telephony is a form of circuit-switched calling that uses a cellular standard wireless interface (typically GSM or CDMA) capable of connecting with the PSTN. More recently, there are cellular wireless interfaces that utilize IP based standards (e.g. LTE or VoLTE) to wirelessly place and receive what are, in effect, VoIP calls since the newer cellular wireless interfaces are IP based rather than circuit-switched. The end result is a vast telecommunications network that provides wireline and wireless inter-connectivity for both circuit-switched devices and VoIP devices.
VoIP traffic can traverse a variety of routers and gateways, in multiple IP networks, between its source and its destination. The VoIP telephony service providers are generally responsible for maintaining a working network to ensure that calls made and received by its customers are completed. When a customer experiences trouble making and receiving calls, the VoIP telephony service provider must quickly discover and correct the problem. Often, there is no way to determine a problem until it is experienced by the customer and reported to the service provider.
What is needed are techniques to monitor the VoIP telephony network and anticipate or discover problems before they significantly affect the customer.